India is the world's most populous democracy. A parliamentary republic with a multi-party system, it has seven recognised national parties, including the Indian National Congress and the Bharatiya Janata Party (BJP), and more than 40 regional parties. The Congress is considered centre-left in Indian political culture, and the BJP right-wing. For most of the period between 1950—when India first became a republic—and the late 1980s, the Congress held a majority in the parliament. Since then, however, it has increasingly shared the political stage with the BJP, as well as with powerful regional parties which have often forced the creation of multi-party coalitions at the centre.

In the Republic of India's first three general elections, in 1951, 1957, and 1962, the Jawaharlal Nehru-led Congress won easy victories. On Nehru's death in 1964, Lal Bahadur Shastri briefly became prime minister; he was succeeded, after his own unexpected death in 1966, by Indira Gandhi, who went on to lead the Congress to election victories in 1967 and 1971. Following public discontent with the state of emergency she declared in 1975, the Congress was voted out of power in 1977; the then-new Janata Party, which had opposed the emergency, was voted in. Its government lasted just over three years. Voted back into power in 1980, the Congress saw a change in leadership in 1984, when Indira Gandhi was assassinated; she was succeeded by her son Rajiv Gandhi, who won an easy victory in the general elections later that year. The Congress was voted out again in 1989 when a National Front coalition, led by the newly formed Janata Dal in alliance with the Left Front, won the elections; that government too proved relatively short-lived, lasting just under two years. Elections were held again in 1991; no party won an absolute majority. The Congress, as the largest single party, was able to form a minority government led by P. V. Narasimha Rao.

A two-year period of political turmoil followed the general election of 1996. Several short-lived alliances shared power at the centre. The BJP formed a government briefly in 1996; it was followed by two comparatively long-lasting United Front coalitions, which depended on external support. In 1998, the BJP was able to form a successful coalition, the National Democratic Alliance (NDA). Led by Atal Bihari Vajpayee, the NDA became the first non-Congress, coalition government to complete a five-year term. In the 2004 Indian general elections, again no party won an absolute majority, but the Congress emerged as the largest single party, forming another successful coalition: the United Progressive Alliance (UPA). It had the support of left-leaning parties and MPs who opposed the BJP. The UPA returned to power in the 2009 general election with increased numbers, and it no longer required external support from India's communist parties. That year, Manmohan Singh became the first prime minister since Jawaharlal Nehru in 1957 and 1962 to be re-elected to a consecutive five-year term. In the 2014 general election, the BJP became the first political party since 1984 to win a majority and govern without the support of other parties. The Prime Minister of India is Narendra Modi, who was formerly Chief Minister of Gujarat.

Government

India is a federation with a parliamentary system governed under the Constitution of India, which serves as the country's supreme legal document. It is a constitutional republic and representative democracy, in which "majority rule is tempered by minority rights protected by law". Federalism in India defines the power distribution between the federal government and the states. The government abides by constitutional checks and balances. The Constitution of India, which came into effect on 26 January 1950, states in its preamble that India is a sovereign, socialist, secular, democratic republic. India's form of government, traditionally described as "quasi-federal" with a strong centre and weak states, has grown increasingly federal since the late 1990s as a result of political, economic, and social changes.

The federal government comprises three branches:

• Executive: The President of India is the head of state and is elected indirectly by a national electoral college for a five-year term. The Prime Minister of India is the head of government and exercises most executive power. Appointed by the president, the prime minister is by convention supported by the party or political alliance holding the majority of seats in the lower house of parliament. The executive branch of the Indian government consists of the president, the vice-president, and the Council of Ministers—the cabinet being its executive committee—headed by the prime minister. Any minister holding a portfolio must be a member of one of the houses of parliament. In the Indian parliamentary system, the executive is subordinate to the legislature; the prime minister and his council are directly responsible to the lower house of the parliament.

• Legislative: The legislature of India is the bicameral parliament. It operates under a Westminster-style parliamentary system and comprises the upper house called the Rajya Sabha ("Council of States") and the lower called the Lok Sabha ("House of the People"). The Rajya Sabha is a permanent body that has 245 members who serve in staggered six-year terms. Most are elected indirectly by the state and territorial legislatures in numbers proportional to their state's share of the national population. All but two of the Lok Sabha's 545 members are directly elected by popular vote; they represent individual constituencies via five-year terms. The remaining two members are nominated by the president from among the Anglo-Indian community, in case the president decides that they are not adequately represented.

• Judicial: India has a unitary three-tier independent judiciary that comprises the Supreme Court, headed by the Chief Justice of India, 24 High Courts, and a large number of trial courts. The Supreme Court has original jurisdiction over cases involving fundamental rights and over disputes between states and the centre; it has appellate jurisdiction over the High Courts. It has the power both to declare the law and to strike down union or state laws which contravene the constitution, as well as to invalidate any government action it deems unconstitutional.

Subdivisions

India is a federation composed of 29 states and 7 union territories. All states, as well as the union territories of Puducherry and the National Capital Territory of Delhi, have elected legislatures and governments, both patterned on the Westminster model. The remaining five union territories are directly ruled by the centre through appointed administrators. In 1956, under the States Reorganisation Act, states were reorganised on a linguistic basis. Since then, their structure has remained largely unchanged. Each state or union territory is further divided into administrative districts. The districts in turn are further divided into tehsils and ultimately into villages.

Foreign relations and military

Since its independence in 1947, India has maintained cordial relations with most nations. In the 1950s, it strongly supported decolonisation in Africa and Asia and played a lead role in the Non-Aligned Movement. In the late 1980s, the Indian military twice intervened abroad at the invitation of neighbouring countries: a peace-keeping operation in Sri Lanka between 1987 and 1990; and an armed intervention to prevent a 1988 coup d'état attempt in Maldives. India has tense relations with neighbouring Pakistan; the two nations have gone to war four times: in 1947, 1965, 1971, and 1999. Three of these wars were fought over the disputed territory of Kashmir, while the fourth, the 1971 war, followed from India's support for the independence of Bangladesh. After waging the 1962 Sino-Indian War and the 1965 war with Pakistan, India pursued close military and economic ties with the Soviet Union; by the late 1960s, the Soviet Union was its largest arms supplier.

Aside from ongoing strategic relations with Russia, India has wide-ranging defence relations with Israel and France. In recent years, it has played key roles in the South Asian Association for Regional Cooperation and the World Trade Organisation. The nation has provided 100,000 military and police personnel to serve in 35 UN peacekeeping operations across four continents. It participates in the East Asia Summit, the G8+5, and other multilateral forums. India has close economic ties with South America, Asia, and Africa; it pursues a "Look East" policy that seeks to strengthen partnerships with the ASEAN nations, Japan, and South Korea that revolve around many issues, but especially those involving economic investment and regional security.

China's nuclear test of 1964, as well as its repeated threats to intervene in support of Pakistan in the 1965 war, convinced India to develop nuclear weapons. India conducted its first nuclear weapons test in 1974 and carried out further underground testing in 1998. Despite criticism and military sanctions, India has signed neither the Comprehensive Nuclear-Test-Ban Treaty nor the Nuclear Non-Proliferation Treaty, considering both to be flawed and discriminatory. India maintains a "no first use" nuclear policy and is developing a nuclear triad capability as a part of its "minimum credible deterrence" doctrine. It is developing a ballistic missile defence shield and, in collaboration with Russia, a fifth-generation fighter jet. Other indigenous military projects involve the design and implementation of Vikrant-class aircraft carriers and Arihant-class nuclear submarines.

Since the end of the Cold War, India has increased its economic, strategic, and military co-operation with the United States and the European Union. In 2008, a civilian nuclear agreement was signed between India and the United States. Although India possessed nuclear weapons at the time and was not party to the Nuclear Non-Proliferation Treaty, it received waivers from the International Atomic Energy Agency and the Nuclear Suppliers Group, ending earlier restrictions on India's nuclear technology and commerce. As a consequence, India became the sixth de facto nuclear weapons state. India subsequently signed co-operation agreements involving civilian nuclear energy with Russia, France, the United Kingdom, and Canada.

The President of India is the supreme commander of the nation's armed forces; with 1.325 million active troops, they compose the world's third-largest military. It comprises the Indian Army, the Indian Navy, and the Indian Air Force; auxiliary organisations include the Strategic Forces Command and three paramilitary groups: the Assam Rifles, the Special Frontier Force, and the Indian Coast Guard. The official Indian defence budget for 2011 was US$36.03 billion, or 1.83% of GDP. For the fiscal year spanning 2012–2013, US$40.44 billion was budgeted. According to a 2008 SIPRI report, India's annual military expenditure in terms of purchasing power stood at US$72.7 billion. In 2011, the annual defence budget increased by 11.6%, although this does not include funds that reach the military through other branches of government. As of 2012, India is the world's largest arms importer; between 2007 and 2011, it accounted for 10% of funds spent on international arms purchases. Much of the military expenditure was focused on defence against Pakistan and countering growing Chinese influence in the Indian Ocean.